In the gasification of coal or petroleum residua to produce fuel gases having low to medium heating value, such as those burned in gas turbines for power production, a major problem is caused by the relatively high sulfur content of such gases. This sulfur must be substantially removed either from the hot fuel gas before combustion or from the stack gas after combustion in order to meet the present environmental pollution standards. Presently known processes for sulfur removal from such fuel gases require first cooling the gas to below about 600.degree.-800.degree. F for an absorption process and then usually reheating it to near the combustion temperature as in the gas turbine. This not only requires substantial heat exchange equipment and its accompanying undesirable expense, but also causes an undesirable reduction in overall thermodynamic efficiency of the process. Removal of sulfur from stack gases after combustion such as by lime scrubbing is also difficult and expensive because of the huge volumes of gas involved.